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More problems setting up IPv6



Hi,

Sorry for bothering you all the time. But I dont have *any* idea whats
going on. Probably I'm kind of idiot but I can't get my stuff up and
running. If you would like to recommend a more appropriate place to
ask my stuff feel fre to do so ...



I will just describe my setup again (some of you know already ..., I
know...).

My little network consists of three computers: toxic, narcotic and crystalline.

"toxic" has a dial-up connection ans sets up a gateway to
freenet6. There is a radvd running on "toxic", its configuration lokks
like this:



,----
| niehaus@toxic:~$ cat /etc/radvd.conf  
| 
| 
| interface eth0
| {
|  AdvSendAdvert on;
|  prefix 3ffe:0bc0:10ab:0001::/64
|  {
|  AdvOnLink on;
|  AdvAutonomous on;
|  };
| };
|  
`----


Well, we need to know about the ethernet configuration:

,----
| niehaus@toxic:~$ /sbin/ifconfig eth0
|           Link encap:Ethernet  HWaddr 00:01:02:26:F7:A7  
|           inet addr:192.168.0.97  Bcast:192.168.0.255  Mask:255.255.255.0
|           inet6 addr: fe80::201:2ff:fe26:f7a7/10 Scope:Link
|           inet6 addr: 3ffe:bc0:10ab:1::1/64 Scope:Global
|           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
|           RX packets:55021677 errors:0 dropped:0 overruns:0 frame:0
|           TX packets:81970054 errors:0 dropped:0 overruns:0 carrier:0
|           collisions:0 txqueuelen:100 
|           RX bytes:167445783 (159.6 MiB)  TX bytes:2721981501 (2.5 GiB)
|           Interrupt:10 Base address:0x7c00 
`----

What surprises me is the link local address with a /10 netmask. 


Okay, the next machine is "narcotic". 


,----
| niehaus@narcotic:~$ /sbin/ifconfig eth0
| eth0      Link encap:Ethernet  HWaddr 00:02:1C:F7:26:78  
|           inet addr:192.168.0.99  Bcast:192.168.0.255  Mask:255.255.255.0
|           inet6 addr: fe80::202:1cff:fef7:2678/10 Scope:Link
|           inet6 addr: 3ffe:bc0:10ab:1:202:1cff:fef7:2678/64 Scope:Global
|           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
|           RX packets:98 errors:0 dropped:0 overruns:0 frame:0
|           TX packets:74 errors:0 dropped:0 overruns:0 carrier:0
|           collisions:0 txqueuelen:100 
|           RX bytes:11322 (11.0 KiB)  TX bytes:10981 (10.7 KiB)
|           Interrupt:11 Base address:0xd800 
`----


got its address with autoconfiguration and has - like "toxic" a /10
netmask for link local. This has been a surprise to me, I wold have
expected to find a /64 netmask, but I dont't know much about IPv6 so
this might be wrong.

Okay. Here is machine number three: "crystalline". 

,----
| niehaus@crystalline:~$ /sbin/ifconfig eth0
| eth0      Protokoll:Ethernet  Hardware Adresse 00:0D:60:8C:3B:BD  
|           inet Adresse:192.168.0.100  Bcast:192.168.0.255  Maske:255.255.255.0
|           inet6 Adresse: 3ffe:bc0:10ab:1:20d:60ff:fe8c:3bbd/64 Scope:Global
|           inet6 Adresse: fe80::20d:60ff:fe8c:3bbd/64 Scope:Link
|           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
|           RX packets:42 errors:0 dropped:0 overruns:0 frame:0
|           TX packets:32 errors:0 dropped:0 overruns:0 carrier:0
|           Kollisionen:0 Sendewarteschlangenlänge:1000 
|           RX bytes:5205 (5.0 KiB)  TX bytes:3729 (3.6 KiB)
|           Basisadresse:0x8000 Speicher:c0220000-c0240000 
`----


After a reboot, it now got a gloabal adress too. But what bothers me:
*this* machine has for whatever reason a /64 netmask in link
local. Just to be sure I just rebooted crystalline an narcotic but
this difference persists.

There is another diffrence: crystalline (with /64 lin local) has a
2.4.26 kernel, toxic and narcotic (both /10 linc local netmask) have a
2.4.18 kernel.


Since crystalline has strange behavior: I took a look at the routing table: 

,----
| niehaus@crystalline:~$ /sbin/ip -6 route show
| 3ffe:bc0:10ab:1::/64 dev eth0  proto kernel  metric 256  expires 2591236sec mtu 1500 advmss 1440
| fe80::/64 dev eth0  metric 256  mtu 1500 advmss 1440
| ff00::/8 dev eth0  metric 256  mtu 1500 advmss 1440
| unreachable default dev lo  proto none  metric -1  error -101
`----

I really don't know the meaning og the last line, but okay....

,----
| niehaus@crystalline:~$ /sbin/ip -6 neigh
| niehaus@crystalline:~$
`----

crystalline has no neihgbours? 


Okay. Im going to ping6 narcotic

,----
| niehaus@crystalline:~$ ping6 3ffe:bc0:10ab:1:202:1cff:fef7:2678
| PING 3ffe:bc0:10ab:1:202:1cff:fef7:2678(3ffe:bc0:10ab:1:202:1cff:fef7:2678) from 3ffe:bc0:10ab:1:20d:60ff:fe8c:3bbd : 56 data bytes
| 64 bytes from 3ffe:bc0:10ab:1:202:1cff:fef7:2678: icmp_seq=1 ttl=64 time=0.511 ms
| 64 bytes from 3ffe:bc0:10ab:1:202:1cff:fef7:2678: icmp_seq=2 ttl=64 time=0.224 ms
| 
| --- 3ffe:bc0:10ab:1:202:1cff:fef7:2678 ping statistics ---
| 2 packets transmitted, 2 received, 0% loss, time 1010ms
| rtt min/avg/max/mdev = 0.224/0.367/0.511/0.144 ms
| niehaus@crystalline:~$
`----

Does not look too bad, eh?


,----
| niehaus@crystalline:~$ /sbin/ip -6 neigh
| fe80::202:1cff:fef7:2678 dev eth0 lladdr 00:02:1c:f7:26:78 nud stale
| 3ffe:bc0:10ab:1:202:1cff:fef7:2678 dev eth0 lladdr 00:02:1c:f7:26:78 nud reachable
| niehaus@crystalline:~$ 
`----

Now we have neighbours....

Let's see, if we can telnet to narcotic:

,----
| niehaus@crystalline:~$  telnet  3ffe:bc0:10ab:1:202:1cff:fef7:2678
| Trying 3ffe:bc0:10ab:1:202:1cff:fef7:2678...
| telnet: Unable to connect to remote host: Connection refused
| niehaus@crystalline:~$ 
`----

Okay. No telnetd running there, lets try to get in touch with Postfix:


,----
| niehaus@crystalline:~$  telnet  3ffe:bc0:10ab:1:202:1cff:fef7:2678 25 
| Trying 3ffe:bc0:10ab:1:202:1cff:fef7:2678...
| telnet: Unable to connect to remote host: No route to host
| niehaus@crystalline:~$ 
`----

Ooops? Suddenly "no route to host"? Strange. The routing table is unchanged:

,----
| niehaus@crystalline:~$ /sbin/ip -6 route show
| 3ffe:bc0:10ab:1::/64 dev eth0  proto kernel  metric 256  expires 2591000sec mtu 1500 advmss 1440
| fe80::/64 dev eth0  metric 256  mtu 1500 advmss 1440
| ff00::/8 dev eth0  metric 256  mtu 1500 advmss 1440
| unreachable default dev lo  proto none  metric -1  error -101
`----

Ping6 stopped working as well. 

,----
| crystalline:/home/niehaus#  ping6 -I eth0 3ffe:bc0:10ab:1:202:1cff:fef7:2678
| PING 3ffe:bc0:10ab:1:202:1cff:fef7:2678(3ffe:bc0:10ab:1:202:1cff:fef7:2678) from 3ffe:bc0:10ab:1:20d:60ff:fe8c:3bbd eth0: 56 data bytes
| From ::1 icmp_seq=1 Destination unreachable: Address unreachable
| From ::1 icmp_seq=2 Destination unreachable: Address unreachable
| From ::1 icmp_seq=3 Destination unreachable: Address unreachable
| 
| --- 3ffe:bc0:10ab:1:202:1cff:fef7:2678 ping statistics ---
| 4 packets transmitted, 0 received, +3 errors, 100% loss, time 3009ms
`----



There is some strange stuff in the logs: 

,----
| Aug  5 22:40:23 crystalline kernel: icmpv6_send: no reply to icmp error
| Aug  5 22:40:44 crystalline last message repeated 13 times
| Aug  5 22:40:50 crystalline kernel: NET: 3 messages suppressed.
| Aug  5 22:40:50 crystalline kernel: icmpv6_send: no reply to icmp error
| Aug  5 22:40:53 crystalline kernel: icmpv6_send: no reply to icmp error
| Aug  5 22:40:59 crystalline kernel: NET: 1 messages suppressed.
| Aug  5 22:40:59 crystalline kernel: icmpv6_send: no reply to icmp error
| Aug  5 22:41:05 crystalline kernel: NET: 1 messages suppressed.
`----


Okay. We compare with "narcotic".

,----
| niehaus@narcotic:~$ /sbin/ip -6 route show
| 3ffe:bc0:10ab:1::/64 dev eth0  proto kernel  metric 256  expires 2591981sec mtu 1500 advmss 1440
| fe80::/10 dev eth0  proto kernel  metric 256  mtu 1500 advmss 1440
| ff00::/8 dev eth0  proto kernel  metric 256  mtu 1500 advmss 1440
| default via fe80::201:2ff:fe26:f7a7 dev eth0  proto kernel  metric 1024  expires 1781sec mtu 1500 advmss 1440
  ^^^^^^^
| unreachable default dev lo  metric -1  error -101
| niehaus@narcotic:~$ 
`----

For some reason, narcotic has an additional default route. 

,----
| niehaus@narcotic:~$ /sbin/ip -6 neigh show
| fe80::20d:60ff:fe8c:3bbd dev eth0 lladdr 00:0d:60:8c:3b:bd nud stale
  ^^^^^^^^^^^^^^^^^^^^^^^^ crystalline
| 3ffe:bc0:10ab:1:20d:60ff:fe8c:3bbd dev eth0 lladdr 00:0d:60:8c:3b:bd router nud stale
  ^^^^^^^^^^^^^^^^^^^^^^^^ crystalline
| fe80::201:2ff:fe26:f7a7 dev eth0 lladdr 00:01:02:26:f7:a7 router nud stale
  ^^^^^^^^^^^^^^^^^^^^^^^  toxic
| niehaus@narcotic:~$ 
`----

These are narcotic's neighbours. 



*Phew* I really don't know how to debug this. Is there anyone who can
give me a hint? I simply don't know where to search for my mistakes.


Thanks,



Sebastian


-- 



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